Hydrography is to many in our profession an unfamiliar word. When in my early days explaining what my job comprised I used to extrapolate it from ‘hydro’ and ‘graphy’, the last component meaning that we wrote down our measurements/findings. And I always added to this the important fact that we were able to retrieve them.
Over the years, archives of survey records, echosounder recordings etc. have grown and grown. Each company or service had (and has) its own system of numbering fairsheets, wrecks and BT-observations and devised overview charts to make it ‘easy’ to trace or compile something. We had a ‘stone-age GIS’.
I notice that organisations involved in land surveying (and related data) are making far more use of GIS than are those working in the marine survey data field; see for examples the content of magazines and conference topics. OK, I know you may consider an ECDIS a GIS - but there is a difference.
Some reasons to explain why GIS is only just making its entry to our profession:
- Our instruments until recently collected only limited amounts of data (e.g. no aerial photography)
- We automated traditional charting most times in such a way as to turn it into a kind of CAD/CAM-process instead of going for a full IT-solution, which is a different conceptual approach
- We work with several integrated specific software solutions, e.g. SSS-equipment, processing and presenting the data in a manufacturer-dependent ‘closed’ circuit
As these solutions fulfil our needs there was, until recently, only limited motivation to use more generic tools, such as GIS.
However: Enormous amounts of data are being generated from our modern instruments and from remote sensing techniques. Computer capacities (both hard- and software) and a drop in prices make implementation of GIS possible in places where until recently costs were the blocking factor. This, together with the growing demand for integration of both information and work processes, will make the way free for the more open and generic solutions offered us by GIS. The modern GIS can (and must) accept variety in the format of both dataset and the instruments and processing packages which deliver them.
GIS-manufacturers will, and already do, notice the increased interest in and use of their products from the ‘wet’ side. It will do no harm for them to tell us the benefits. We, as surveyors (and the scientists who will inevitably use our data), have to make sure that our requirements are known to the GIS-people. Are we (and they) aware that in the '70s a lot of data was transformed into digital datasets (e.g. put onto big magnetic tape reels), but that many analogue records - like SSS-recordings - stayed in the folders as it was too difficult or too costly to transform them? With a bit of luck they are still hanging around somewhere in dusty folders or cardboard boxes.
Our marine survey data, on average more costly to collect than is land data, deserves widespread usage far beyond our own direct purposes in collecting it. By mapping, charting and visualising in 3-D and 4-D GIS can help us to understand the processes on our earth, which is for 70 per cent covered with the medium in and upon which we work.
Enjoy reading,
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